Scientists trip light fantastic amid fresh doubt on Einstein

Physicists have carried out an improved version of an earlier experiment, which left scientific experts around the world astounded when the initial results were made public in September.

The tests suggest that sub-atomic particles called “neutrinos” can break the barrier – and challenge a dogma of science that has been held since 1905.

The new experiment at the Gran Sasso laboratory, in Italy, using a neutrino beam from the Cern nuclear research centre in Switzerland, 450 miles away, was held to check the earlier findings, which were greeted with scepticism by many in the scientific community.

Critics of the first report in September had said that the long bunches of tiny particles used could introduce an error into the test. The new work used much shorter bunches.

Scientists yesterday submitted their latest findings to the Journal of High Energy Physics for consideration. A light beam would take 2.4 milliseconds to travel the distance – but both experiments have shown a neutrino can beat it there by 60 billionths of a second.

In 1905, Einstein stated in his theory of special relativity that nothing can travel faster than a light beam in a vacuum – 168,282 miles per second.

According to the theory, it would take an infinite amount of energy to exceed light speed.

Fernando Ferroni, president of the Italian Institute for Nuclear Physics, said: “A measurement so delicate and carrying a profound implication on physics requires an extraordinary level of scrutiny.

“The positive outcome of the test makes us more confident in the result, although a final word can only be said by analogous measurements performed elsewhere in the world.”

Jacques Martino, director of the French National Institute of Nuclear and Particle Physics, who worked on the second experiment, said that while this test was not a full confirmation, it did remove some of the potential errors that may have occurred in the first one.

Physicists in Japan will now try to repeat the experiment, with the help of scientists from Liverpool University.

The idea that nothing can exceed the speed of light in a vacuum forms a cornerstone in physics – first laid out by Scottish physicist James Clerk Maxwell and later incorporated into German-born Einstein’s theory of relativity.

If confirmed, scientists say the findings may show that Einstein was wrong when he set out in his theory of special relativity that the speed of light is a “cosmic constant” and nothing can go faster. This would force a major rethink of theories about how the cosmos works and even mean it would be possible, in theory, to send information into the past.

Professor Themis Bowcock, head of the university’s particle physics team, said: “Should neutrinos travel faster than light, it would overthrow our ideas of the structure of space and time.

“Physicists are therefore treating the results of the experiment with caution and looking to test them again through our separate experiments to be certain of what these results are telling us.”

Jim Al-Khalili, a physics professor at Surrey University, whose reaction to the first “faster-than-light” results was that he would “eat his shorts” if they turned out to be true, yesterday said he remained unconvinced.

“Ideally, the experiment would have to be done somewhere else entirely to try to verify the controversial result that these tiny particles really are going faster than light,” he added.